Maybe it is the luck of the draw, especially since there are more Skywards Gold members these days. Just don't hold your breath for free upgrades with status, I guess it depends on the value of your ticket as well. If you get it, then great!
I've been a Gold member for over 2 years now and only started getting upgraded on flights this year from J to F (twice). Next time I get upgraded, I hope it's on a long haul flight (private suite possibly???)